Vertebral Column & Thoracic Cage Flashcards
Vertebral column
Extends from skull to pelvis, and forms the body’s major axial support. Surrounds and protects the spinal cord. Consists of 24 vertebrae and two fused bones, the sacrum and coccyx.
What are the different types of vertebrae?
Cervical: 7 bones of the neck
Thoracic: 12 bones
Lumbar: the 5 bones supporting the lower back
Sacral curvature: sacrum, 5 fused vertebrae
Coccyx: 4 fused vertebrae
Differentiate between vertebrae, vertebral column, and spinal cord.
The vertebral column surrounds and protects the spinal cord, and consists of 24 single bones, called vertebrae.
Intervertebral discs
Pads of fibrocartilage that separate the vertebrae, as well as cushion the vertebrae and absorbs shock.
Two major regions of the intervertebral discs
Nucleus pulposus: central gelatinous region that behaves like a rubber ball
Annulus fibrosis: outer ring of encircling collagen fibers that stabilizes the disc and contains the nucleus pulposus
Normal spinal curvatures: primary
Primary curvatures: thoracic (convex) and sacral (convex) curvatures; considered primary because they are present and well developed at birth
Normal spinal curvatures: secondary
Secondary curvatures: cervical (concave) and lumbar (concave); formed later
Abnormal spinal curvatures
Scoliosis: lateral deformity
Kyphosis: hunched back
Lordosis: sway back; exaggerated curve in lumbar region
Identify the structural features of a typical vertebra.
pg. 134, Figure 9.15
What are the defining characteristics of cervical vertebrae?
Smallest and lightest vertebrae.
Vertebral foramen is triangular.
Spinous process is short and often bifurcated (divided into two branches).
Atlas (C1)
No body.
No spinous process.
Lateral processes contain large concave depressions on their superior surfaces that receive the occipital condyles of the skull (enables you to nod yes).
Axis (C2)
Contains large vertical process, the dens, that serves as the pivot point.
C7
Vertebral prominens (spinal process is visible through the skin at the base of the neck).
What are the characteristics of the thoracic vertebrae?
Larger body, somewhat heart shaped.
Costal facets (articulating surfaces) on each side of the body, that articulate with the heads of the corresponding ribs.
Vertebral foramen is round/oval.
Spinous process is long, with a sharp downward hook.
What are the characteristics of lumbar vertebrae?
Large, blocklike bodies.
Short, thick, hatchet-shaped spinous processes extending directly backward.
Sacrum
Composite bone formed from the fusion of five vertebrae.
What are the features of the sacrum?
Superior articular processes on first sacral vertebra.
Median sacral crest: remnant of the spinous processes of the fused vertebrae
Alae: winglike structure, formed by fusion of the transverse processes, articulate laterally with the hip bones
Sacral foramina: located at either end of the transverse ridges, allow blood vessels and nerves to pass
Sacral canal: continuation of the vertebral canal
Sacral hiatus: large opening near the coccyx where the sacral canal ends
Sacral promontory: anterior border of the body of S1
Coccyx
4 fused vertebrae.
Tailbone.
Attached to the sacrum by ligaments.
Thoracic cage
Bony thorax; composed of the sternum, ribs, thoracic vertebrae, and costal cartilages.
Sternum
Breastbone; typical flat bone that is the result of the fusion of the manubrium, body, and xiphoid process. Attached to the first seven pairs of ribs.
Manubrium
Superiormost, looks like knot of tie.
Body (sternum)
Forms the bulk of the sternum.
Xiphoid process
Constructs the inferior end of the sternum and lies at the level of the fifth intercostal space.
What are the bony landmarks of the sternum?
Jugular notch (concave upper border of the manubrium) Sternal angle Xiphisternal joint (the point where the sternal body and xiphoid process fuse)
